Restrictor valves



lh 195@ u. ks. DlcKlNsoN ?82(3,217`

RESTRICTOR VALVES I Fmed Nov. 14, 1952 Vig. z.

\ lll/llInlill/Illllllllllllllllllllllh His ,AL-torn@ l United StatesPatent O RESTRICTOR VALVES Daniel S. Dickinson, Louisville, Ky.,assignor to General Electric Company, a corporation of New YorkApplication November 14, 1952, Serial No. 320,379

2 Claims. (Cl. 137-505.120)

My invention relates to load limiting devices and more particularly tosuch devices used in connection with refrigeration apparatus forautomatically limiting to a predetermined maximum the load on thedriving motor.

Following an extended idle period of a refrigerator, such as duringstorage or shipping, the refrigerant pressure on the suction or normallylow pressure side of the compressor and the refrigerating systememployed for cooling the refrigerator rises considerably. Duringpulldown, or the period required by the compressor to come up to speedfollowing an extended idle period, this high pressure on the suctionside of the compressor results in considerable loading of the motordriving the compressor. Such heavy motor loading is encountered alsoduring normal operation when the refrigerator is Well stocked with heatladen items. One manner of coping with this situation is to provide therefrigerator with a motor large enough to operate `easily underabnormally heavy loading conditions. This, however, would result in pooreconomy in space and materials and inefficient motor operation undernormal conditions. From the standpoints of good economy in space andmaterials and high efficiencyv in motor operations, it is desirable toemploy a small motor having a capacity just sufficient for driving thecompressor satisfactorily under normal conditions. When such a motor isemployed, it is essential to provide means for limiting to apredetermined maximum the pressure at the suction side |of thecompressor thereby to avoid overloading of the moto-r during pulldown orduring starting of the compressor under abnormally heavy refrigeratorloads. n

The primary object of my invention is to provide a new and improvedarrangement for avoiding overloading of a compressor motor by limitingto a predetermined maximum the pressure at the suction side of thecompressor.

Further objects and advantages `of my `invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming part of this specification.

In carrying out the objects of my invention, I provide a housing adaptedfor connection to the low pressure side of a compressor, porting meansfor admitting refrigerant into the housing and valve means cooperatingwith the porting means. The valve means includes a plunger, and when thepressure drop across the plunger exceeds a predetermined maximum, theporting means is rendered ineffective. Means tending to equalizepressure across the plunger is effective when the porting means isineffective for decreasing the pressure drop below the predeterminedmaximum for thereby rendering the porting means again eifective.

For a better understanding of my invention, reference may be had to theaccompanying drawing in which Fig. 1 is a schematic4 representation of arefrigerating system.

2,826,217 Patented Mar. 11, 1958 ICC Fig. 2 is an end view partiallybroken away of the refrigerating unit shown in Fig. 1.

Fig. 3 is an enlarged sectional elevation view of a portion of Fig. 2showing details of the load limiting device.

And Fig. 4 is an enlarged sectional elevation view of a secondembodiment of the load limiting device.

In Fig. l there is shown a refrigerating system including a condenser 1,an evaporator 2 and a refrigerating unit 3. The flow of refrigerant fromthe condenser to the evaporator is controlled by a capillary tube 4.Compressed refrigerant is supplied to the condenser 1 from therefrigerating unit 3 through a conduit 5 and vapor- `ized refrigerant isreturned to the refrigerating unit from the evaporator 2 through aconduit 6.

As better seen in Fig. 2, the refrigerating unit 3 comprises ahermetically sealed case 7 and a compressor 8 arranged in the case. Thecompressor 8 is driven by a suitable motor (not shown). Through theconduit 6 the case 7 receives vaporized refrigerant from the evaporator2. The vaporized refrigerant passes to the suction side of thecompressor 8 through a load limiting device 9 and an intake muffler 10also arranged Within the case.

Referring now to Fig. 3, the load limiting device 9 includes a housing11. Provided in the upper portion of the housing 11 is a refrigerantoutlet 12. A tube 13 connects the outlet 12 of the housing 11 with theintake mufer 10. Tubes 15 and 16 connect the intake mutller 10 with thesuction or low pressure Side of the compressor 8. Thus the housing 11 isconnected to the low pressure side of the compressor 8. Compressedrefrigerant is discharged from the compressor 8 through a conduit 17into an exhaust mufer 18 and passes from the exhaust muffler to thecondenser 1 through the conduit 5.

As seen in Figs. 2 and 3, the load limiting device 9 includes portingmeans for admitting refrigerant from the case 7 into the housing 11. Theporting means comprises a conduit 19 extending transversely through thelower portion of the housing 11 and having both extremities open forreceiving refrigerant from the case 7. To increase the effectiveness ofthe conduit 19 in admitting refrigerant into the housing from the case,the conduit is so formed that one extremity designated 20 extendshorizontally while the other extremity designated 21 extends vertically.Additionally, both extremities 20 and 21 are flattened slightly. v

In the housing 11, the conduit 19 is formed with .a reduced portion 22.Formed in the reduced portion 22 for providing communication between theyconduit and the housing is a pair of opposed orilioes 23. Furtherincluded in the load limiting device 9 is valve means for cooperatingwith the porting means. The valve means includes a plunger 24 adaptedfor operating in the housing between the outlet 12 and the conduit 19.The plunger 24 is weighted and fits loosely in the housing 11. Formedadjacent each end of the plunger 24 is a peripheral groove 25. Providedfor fitting in the peripheral grooves 25 are spring wire members 26,each of which is formed with a plurality of spaced apart radialprojections 27. The projections 27 slidingly engage `the vinterior wallsof the housing 11 and are effective for maintaining a predeterminedclearance or space, indicated by 430, between the plunger 24 and thehousing 11. The space 30 tends to equalize pressure across .the plunger.In the arrangement described to this point, the

plunger 24 is adapted for lifting from and falling to the 24 at thebottom of the recess 31 and extending toward the orifices 23 is afiexible element or wire 34. Suitably secured to the free end of thewire 34 and extending through the orifices 23 is a member or valve stem35. For a purpose which will be explained in detail hereinafter therecess 31 and the wire 34 render the valve stem 35 movably outwardlyfrom the vertical axis of the plunger. Formed on the Valve stem 35 is apair of spaced apart spherical portions 36. One of the sphericalportions 36 is disposed in the conduit 19 and is adapted for cooperatingwith the upper one of the orifices 23. The other of the portions 36 isdisposed below the conduit 19 and cooperates with the lower one of theorifices 23. It will be seen that while I prefer employing opposedorifices in the conduit and a pair of spherical portions on the valvestem, satisfactory performance of the device could be obtained with asingle orifice and a single cooperating spherical portion.

The weight of the plunger 24 biases the valve stem 35 to the positionthereof shown in Fig, 3, in which position the spherical portions 36 arerendered unrestrictive with respect to refrigerant flow from the conduit19 through the orifices 23 and into the housing if. It will be seen thatthe plunger and the valve stem may be biased to the position of Fig. 3by a spring if it is not desired to rely on the weight of the plunger orif the housing is to be mounted horizontally and a weighted plungercannot be employed.

When the pressure of refrigerant in the evaporator 2 and therefore, inthe case 7, increases and results in a pressure drop across the plunger24 sufficient for overcoming the biasing effect of the plunger, theplunger lifts and, through the flexible connection 34 between theplunger and the valve stem, moves the spherical por tions 36 of thevalve stern toward the orifices 23. In accordance with the pressure dropacross the plunger 24 and the amount of the resultant lift of theplunger the ow of refrigerant through the orifices 23 is restricted bythe spherical portions 36, or in other words, the effectiveness of theporting means in admitting refrigerant into the housing for conductionto the compressor is varied.

When the pressure drop across the plunger 24 exceeds a predeterminedmaximum, as will be the case during pull-down or starting underunusually heavy loading of the refrigerator, the amount of lift of theplunger 24 will be such as to move the spherical portions 36 into theorifices 23 for thereby closing the orices. With the orifices 23 closedin this manner, the refrigerant is no longer admitted into the housing11 from the case 7 and the pressure at the suction side of thecompressor, and therefore, the load on the motor driving the compressor,are limited to a predetermined maximum. The compressor 8, however,continues to operate and draws refrigerant across the plunger throughthe space 30. Thus, the pressure drop across the plunger is slowlyreduced below the predetermined maximum and the plunger slowly fallstoward the position of Fig. 3. The plunger in falling causes thespherical portions of the valve -stem-to move slowly downwardly out ofthe orifices 23 whereby the orifices are again rendered effective foradmitting refrigerant into the housing 11 from the conduit 19. Theamount of refrigerant admitted into the housing will be sufficient tocause the plunger 24 to assume, and be maintained in during subsequentnormal operation, a lifted position in which the spherical portions 36restrict to the predetermined maximum the amount of refrigerant flowthrough the orifices 23.

It will `be seen that the mentioned predetermined maximum to which thedevice 9 limits the fiow of refrigerant to the compressor is dependentupon, and may be varied by varying, one or more of a number of factors.These factors are the weight and area of the plunger 24, the clearance30 between the plunger and the housing, and the clearances between thespherical portions 36 on the valve stem 35 and the orifices 23.Additionally, while I have shown the spherical portions 36 as being sospaced apart that they would simultaneously close and simultaneouslyopen their respective orifices, it will be seen that they may be sospaced as not to close and open the orifices simultaneously for therebyvarying the flow restricting characteristics of the device.

In the device 9 the flexible connection between the plunger 24 and thevalve stem 35, as effected by the flexible wire 34, and the taperedsurfaces of the spherical portions 36 are effective for affordingself-alignment of the valve stem and the spherical portions thereon withthe orifices 23. This self-alignment feature eliminates the need foraccurately machined components and, consequently, results in a costreduction. While I have shown the portions 36 as being spherical, itwill be seen that they may Ybe of any configuration which providestapering surfaces for cooperating with the orifices Z3. For instance,they could be conical.

Provided for minimizing jet reaction of refrigerant flowing through theupper one of the orifices 23 on the interior surfaces of the recess 31is a bafiie member 37. The bafiie member 37 is formed with a pluralityof horizontal radial tabs 38. The tabs 33 rest on and are suitablysecured to an interior shoulder 39 formed in the housing 11. Also formedon the baffle member 3'7 and alternating with the horizontal tabs 33 areupwardly bent tabs 463. The upwardly bent tabs 40 provide a seat for theplunger 24 when the plunger is in its downward position. Additionally,the tabs 40 permit the passage of refrigerant from the lower portion ofthe housing lll to the upper portion. Centrally formed in the baiemember 37 is an aperture 41. The aperture 41 permits extension of thevalve stern 35 through the baffle 37 and is sufficiently large forpermitting lateral movement of the valve stem 35 necessary to theself-alignment of the spherical portions on the stem with the conduitorifices.

In Fig. 4 there is shown a second embodiment of my load limiting devicegenerally designated 45. The device 45 comprises a housing 46 includingan outlet 47 formed in the upper portion of the housing, and portingmeans comprising a plurality of radially spaced lateral intake ports 48.As seen in Fig. 4, the intake ports 48 may be key-hole shaped. Thedevice 45 is adapted for being arranged in the case 7 of therefrigerating unit 3 in the same manner as the above described firstembodiment 9. A tube 49 is provided for connecting the outlet 47 of thehousing 46 to the intake mufiier 10. The device 45 further comprisesvalve means including a plunger 5f) adapted for operating in the housing46 and cooperating with the porting means. The plunger 50 is weightedand fits loosely in the housing. The weight of the plunger 50 biases theplunger for being seated in the lower end of the housing 46 in themanner shown in Fig. 4. In this form of my invention, also, the plungerinstead of being weighted could be biased by a spring.

The plunger 50 is formed to include a reduced intermediate portion 51.When the plunger 5t) is seated in the bottom of the housing 46 in themanner shown in Fig. 4, the reduced portion 51 is in register with theintake ports 48. The reduced portion 51 divides the plunger into anupper or first plunger portion 52 and a spaced apart second or lowerplunger portion 53. The upper portion 52 is adapted for operatingbetween the outlet 47 and the intake ports 48, and the portion 53 isadapted for cooperating with the lateral ports 48 to determine therefrigerant fiow therethrough. Provided for affording refrigerant fiowacross the upper portion 52 of the plunger 50 is a refrigerant passage54. Provided for affording refrigerant fiow across the lower portion 53of the plunger 50 is a bleeder passage 55. As pointed out above, theplunger 50 fits loosely in the housing 46. In this manner, a clearance56 is provided between the plunger and the housing. The refrigerantpassage 54 tends to equalize pressure across the upper portion 52; thebleeder passage 55 tends to equalize pressure across the lower portion53; and the passages 54 and 55, together with the clearance 56, all tendto equalize pressure across the plunger 50 as a whole. As a result,refrigerant entering the housing 46 through the lateral intake ports 48tends to flow past the plunger and through the outlet 47 and the tube 49to the compressor.

The weight of the plunger 50 biases the plunger to the position thereofshown in Fig. 4, in which position the lower portion 53 is renderedunrestrictive with respect to refrigerant flow through the ports 48 andinto the housing 46 for conduction to the compressor 8. When thepressure of refrigerant in the case 3 increases and results in apressure drop across the plunger sufficient for overcoming the biasingeffect of the plunger, the plunger lifts. ln accordance with thepressure drop across the plunger 50 and the amount of resultant lift ofthe plunger, the flow of refrigerant through the lateral ports 48 isrestricted by the lower portion 53 of the plunger. Or in other words,the lower portion 53 of the plunger varies the effectiveness of theporting means in admitting refrigerant into the housing for conductionto the compressor. During pull-down, or starting under unusually heavyloading of the refrigerator, the pressure drop across the plunger 50exceeds a predetermined maximum and the plunger lifts to a point wherethe lower portion 53 effectively closes the lateral ports 48. With thelateral ports 48 closed in this manner, refrigerant is no longeradmitted into the housing 46 from the case 7 and the pressure at thesuction side of the compressor, and therefore, the load on the motordriving the compressor, are limited to a predetermined maximum.Operation of the compressor 8, however, draws refrigerant across theplunger 50 through the refrigerant passage"`54 and the bleeder passage5S, and in this manner the pressure drop across the plunger is slowlyreduced below the predetermined maximum. The plunger slowly falls towardthe position of Fig. 4 and the lower portion 53 thereof opens thelateral ports 48 again for admitting refrigerant into the housing 46from the case 7. The amount of refrigerant admitted into the housingwill be sufficient to cause the plunger 50 to assume, and be maintainedin during subsequent normal operation, a lifted position in which thelower portion 53 thereof restricts to the predetermined maximum theamount of refrigerant flow through the intake ports 48.

It will be seen that the mentioned predetermined maximum to which thedevice 45 limits the flow of refrigerant to the compressor is alsodependent upon, and may be varied by varying, one or more of a number offactors. In the device 4S these factors are the Weight and area of theplunger 50, the diameters of the passages 54 and 55, the clearance 56between the plunger and the housing, and the number of and configurationof the lateral intake ports 48.

Provided for minimizing side thrust of the plunger 50 in the housing 46is a plurality of spaced apart peripheral grooves 57 formed in both theupper and lower portions 52 and 53, respectively, of the plunger 50. Thegrooves 57 minimize side thrust by equalizing pressure about the plunger50.

While I have shown and described specific embodiments of my invention, Ido not desire my invention to be limited to the particular forms shownand described and I intend by the appended claims to cover allmodifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A pressure valve for limiting to a predetermined maximum the pressureof gas passing therethrough comprising a housing having outlet portingmeans and inlet porting means, the latter including a conduit extendingtransversely in said housing, said conduit including a pair of inletorifices for admitting gas from said conduit into said housing, andvalve means in said housing, said valve means including a weightedplunger slidable in said housing between said inlet and outlet portingmeans, spacing means maintaining a space between said plunger and saidhousing to provide for the flow of gas therebetween so that gas may owto said outlet porting means and also so that there is the tendency forgas pressure across said plunger to equalize, said plunger having wallsdefining a recess extending upwardly from the bottom of said plunger, aflexible element in said recess secured to said plunger, a valve stemsecured to said flexible element having a pair of spaced sphericalportions, said spherical portions being movable into said orifices forrestricting the iiow of gas therethrough, said flexible element and thecontours of said spherical portions affording self-alignment of saidspherical surfaces with said orifices, said spherical surfaces beingbiased by the weight of said plunger to positions wherein they do notrestrict the gas flow through said orifices, and moved to positions torestrict gas flow through said orifices by said plunger in accordancewith the pressure drop across said plunger, and finally to positions toclose said orices when said pressure drop exceeds a predeterminedmaximum, said space between said plunger and housing being effectivewhen said orifices are closed for decreasing said pressure drop belowsaid predetermined maximum thereby to permit said plunger to move toreopen said orifices.

2. A pressure valve for limiting to a predetermined maximum the pressureof gas passing therethrough comprising a housing having -outlet portingmeans and inlet porting means, the latter including a conduit extendingtransversely in said housing, said conduit including a pair of opposedinlet orifices for admitting gas from said conduit into said housing,and valve means in said housing, said valve means including a Weightedplunger movable between said inlet and outlet porting means, spacingmeans maintaining space between said plunger and said housing, saidspace providing for the flow of gas around said plunger so that gas mayflow to said outlet porting means and so that there is the tendency forgas pressure across said plunger to equalize, said plunger having wallsldefining a recess in the underside of said plunger, a flexible eleme-ntin said recess secured to said plunger, said flexible element extendingtoward said orifices, a valve stem secured to said flexible element,said valve stem including a pair of spaced spherical portions, saidspherical portions being movable into said orifices for restricting theflow of gas through said orifices, said fiexible element and thecontours of said spherical portions affording self-alignment of saidspherical portions with said orifices, said spherical portions beingbiased to open position with respect to said orifices by the weight ofsaid plunger and moved to gas flow restricting positions with respect tosaid orifices by said plunger in accordance with the pressure dropacross the plunger, and finally to positions to close said orifices whensaid pressure drop exceeds a predetermined maximum, said space betweensaid plunger and housing being effective when said orifices are closedfor decreasing said pressure drop below said predetermined maximumthereby to reopen said orifices, and a baffle element within saidhousing adjacent said plunger for minimizing jet reaction against saidplunger of gas flowing through said orifices.

References Cited in the file of this patent UNITED STATES PATENTS257,069 Reznor Apr. 25, 1882 331,008 Spear Nov. 24, 1885 400,173 BellMar 26, 1889 1,065,973 Shatfner Iuly 1, 1913 1,238,051 Peterson Aug. 21,1917 1,628,654 Cissell May 17, 1927 2,497,668 Grumblatt Feb. 14, 19502,520,386 Dillman Aug. 29, 1950 2,633,868 Berhoudar Apr. 7, 1953

